Supramolecular Binding and Extraction of Phosphate, Phosphite and Fluorophosphate Anions from Water by Nanojars

High Resolution Image Download MS PowerPoint Slide In this work, the supramolecular binding of HPO 4 2–, HPO 3 2– and FPO 3 2– ions by nanojars of the general formula [XPO 3 2– ⊂{ cis -Cu II (μ-OH)(μ-pz)} n ] 2– ( Cu n XPO 3; X = HO, H, F; n = 27–33; pz = pyrazolate) was explored. The nanojar hosts, which consist of stacks of three Cu x ( x = 6–14, except 11) metallamacrocycles, were studied in solution by electrospray-ionization mass spectrometry, variable-temperature, paramagnetic 1 H NMR and UV–vis spectroscopy, whereas the entrapped anion was probed using 19 F and 31 P NMR spectroscopy. In the solid state, X-ray diffraction on nine different single-crystals offers valuable information about the structure of the host–guest complexes ( Cu 7+13+9 HPO 4, Cu 8+13+8 HPO 4, Cu 8+13+8 HPO 3, and three pseudopolymorphs each for Cu 8+14+9 HPO 3 and Cu 8+14+9 FPO 3 ) and details of the supramolecular binding of the different phosphorus anions. Multinuclear NMR studies reveal that the different XPO 3 2– ions induce dramatic changes in the magnetism of a given nanojar, despite a less striking difference observed in their respective crystal structure, pointing to significantly different solution structures. The formation of HPO 3 2– and HPO 4 2– nanojars by anion exchange from CO 3 2– was also studied, along with the effects of NH 3 and Ba 2+ ions on nanojar composition and thermal stability in solution. Furthermore, the liquid–liquid extraction of the HPO 4 2–, HPO 3 2– and FPO 3 2– anions from water into an organic solvent was demonstrated using nanojars as extractants.